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000
FXUS64 KEWX 242020
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
320 PM CDT TUE MAY 24 2016

.SHORT TERM (Tonight through Wednesday Night)...

Main highlight for the next 36 hours will be Wednesday evening as
the first round of potentially heavy rain moves across the Rio
Grande Plains and Hill Country. This area will shift east Thursday
with several rounds possible by late week. See long term
discussion below for more on this time-frame and associated
weather hazards.

Slightly stronger H5 588DM ridging is helping suppress overall
shower activity across the region with only some light showers
across the coastal plains and east of the I-35 corridor.
Instability is growing once again across north Mexico with storm
development expected again there this afternoon. However, stronger
capping is in place higher in the terrain and this should keep
any storm that does develop from reaching the border. By Wednesday
morning, low clouds will persist with high humidity values
remaining in place. PWATS will be near 1.8" along and south of the
Escarpment by Wednesday afternoon as a surface low pressure system
develops across the lee-side of the Rocky Mountains. Low-level
wind field velocities will increase by late Wednesday into
Thursday morning and help draw up very moist air from the Tropics.
PWATS look to increase to near 2" near midnight Thursday morning
coincidentally with a stronger ejecting shortwave impulse ahead of
the main parent trough over the desert SW. See long term below for
more on this heavy rainfall set-up into the late week.

&&

.LONG TERM (Thursday through Tuesday)...

Focus will continue on the heavy rain potential Thursday and into
the beginning of Memorial day weekend. A flash flood watch may be
needed for this time frame as evolution and details become more
clear. Please stay tuned for further updates.

What is clear is that the overall synoptic pattern of vertical
lift, ample deep moisture, and instability could lead to localized
pockets of heavy rainfall across the region. The entire region
has been placed in slight risk for excessive rainfall leading to
flash flooding. At this time, widespread average amounts of 1-3
inches with localized 4" appears likely. With the saturated soil
from the above normal rainfall already, localized areas will not
need much to cause flooding issues.

By Thursday morning, H925 to H850 theta-e air will be 345-350K and
14-16 g/kg mixing ratios are modeled to be in place over south-
central Texas with increasing divergence over the region. This
set-up could support moderate to heavy rain at times as forcing
moves east. One possible bust of heavy rain will be if the impulse
moves slightly farther south and forms a large complex along the
coast and thus cutting this area off from additional moisture
inflow. If this occurs, overall rainfall amounts could be reduced.
Depending on evolution, the severe weather potential for the
afternoon will need to monitored. If the activity forms farther
north and then shifts out by early afternoon, a second round of
showers and storms could take shape across the Hill Country into
the I-35 corridor. Again, heavy rain could occur with this round
as well. Hail and damaging winds could also occur in some of the
stronger storms given progged 2500 J/KG CAPE values along with
supporting wind shear.

Models diverge Thursday night into Friday with the GFS persistent
on additional shortwave energy riding over the region whereas the
EC shifts energy NE of the area for a brief lull as the main
parent trough moves across north Texas. The GEM lies in between
with some residual showers ongoing through Friday morning. By
Friday afternoon, stronger forcing from the passage of the main
trough will swing across north Texas and help redevelop showers
and thunderstorms. This activity should swipe through at least
the central and east areas. The line should be progressive enough
that will help reduce rainfall duration but any rain that falls on
top of already soaked grounds will lead to flooding issues. Strong
to severe storms could again be possible Friday as the dryline
shifts farther east.

For Memorial Weekend, 30-40% chance showers and thunderstorms
remain as SW flow aloft continues in a moist and unstable airmass.
While a complete washout is not expected, pop-up showers and
thunderstorms will need to be closely monitored by those with
outdoor plans.

The active pattern will persist into early next week with at least
low to moderate rain chances remaining in the forecast.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              74  88  73  81  71 /  20  10  40  70  60
Austin Bergstrom Intl Airport  75  88  73  81  72 /  20  10  40  70  60
New Braunfels Muni Airport     75  88  73  82  72 /  20  10  50  70  50
Burnet Muni Airport            72  86  71  81  70 /  10  10  50  70  60
Del Rio Intl Airport           76  90  73  87  71 /  20  20  70  30  50
Georgetown Muni Airport        74  87  73  80  71 /  20  10  40  70  60
Hondo Muni Airport             75  89  74  85  72 /  10  10  60  60  50
San Marcos Muni Airport        74  87  72  80  72 /  20  10  50  70  50
La Grange - Fayette Regional   76  87  74  82  73 /  20  10  40  70  50
San Antonio Intl Airport       75  88  73  82  72 /  10  10  50  60  50
Stinson Muni Airport           76  89  74  84  73 /  10  10  50  60  50

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...Oaks
Synoptic/Grids...Allen
Public Service/Data Collection...33





000
FXUS64 KEWX 241832
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
132 PM CDT TUE MAY 24 2016

.AVIATION... /18z TAFs/

Steady onshore flow will keep an abundance of low level clouds
over the are through the TAF periods. Mixing this morning from an
active low level jet contributed to an early dispersal of IFR cigs
and early improvements to VFR skies in some cases. the low level
winds should be similar to late tonight, so will apply some
persistence to periods where guidances show poor agreement. No
significant coverage of precipitation is expected to impact taf
sites through the respective valid periods.

&&

.PREV DISCUSSION... /ISSUED 326 AM CDT TUE MAY 24 2016/

SHORT TERM (Today through Wednesday)...

Mostly cloudy skies are prevailing across the region with ample
low-level moisture in place. There have been a couple of
observation sites reporting brief light rain and will include the
mention of sprinkles in the morning hours. For this afternoon,
things should be a bit quieter across the region. High-res
guidance shows some showers across the eastern zones once again
and will show the higher pops (20s) in this area. The dryline will
be just west of the region this afternoon and can`t rule out an
isolated thunderstorm moving into the western CWA late this
afternoon or evening. There will be a conditional threat of severe
weather as the atmosphere would support severe convection. Will
mention thunderstorms in the official forecast with only a 10 pop
as the threat is low.

On Wednesday, an upper trough will be moving east and will be
centered near southern California. Ahead of this feature, models
are progging a shortwave trough embedded in southwest flow aloft
to move into the region. This feature will help aide in the
development of shower and thunderstorm activity in the late
afternoon and evening hours out west along the dryline. There
will be a CAP in place initially but both the GFS and ECMWF are
progging decent amounts of QPF across the western CWA which
indicates the CAP is likely to break as convective temps are met.
CAPE values in the late afternoon evenings will be near 3500 J/Kg
and there will be a threat of severe storms with any activity that
develops across the northwestern CWA. Large hail would be the main
threat with steep mid-level lapse rates in place.

LONG TERM (Wednesday Night through Monday)...

For Wednesday night, there should be some sort of convective
complex ongoing assuming storms do develop in the late afternoon
hours. Severe chances would likely diminish in the overnight
period with the loss of day time heating.

Thursday and Thursday night, the previously mentioned upper
trough will be approaching West Texas and the Panhandle. As this
feature moves closer, large scale forcing for ascent will be on
the increase. The best lift will be north of the CWA and the bulk
of the storm activity should be north of the region as well.
However, there remains decent chances for thunderstorms in the
CWA especially in the evening hours. There is an enhanced risk of
severe storms just north of the region with a slight risk along
and west of the I-35 corridor. 850 winds will be from the south
around 35 knots in the afternoon with 0-3km helicity values near
250 m2/s2. In addition to a large hail risk there would also be a
possible isolated tornado risk as well.

The base of the upper trough will move into the southern plains
on Friday and as this occurs, the dryline should be able to push
farther east in the afternoon hours. This should ensure that the
bulk of the shower and storm activity will be east of I-35 mainly
east of the dryline. The dryline will retreat back to the west by
Saturday morning and the better convection chances Saturday
afternoon will be across the western half of the area. Once again,
CAPE and shear values will support the threat of severe convection
with any cells that are able to be be sustained in the boundary
layer.

On Sunday, another shortwave trough will move north of the region
and the bulk of the activity will remain north of the CWA. Can`t
rule out an isolated shower or storm and will keep a 20 PoP in the
forecast. The same can be said for Monday as most of the storms
will remain near the dryline which is expected to be west of the
region.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              88  74  89  73  82 /  20  10  20  40  70
Austin Bergstrom Intl Airport  88  75  89  73  82 /  20  10  20  40  70
New Braunfels Muni Airport     89  75  89  73  83 /  20  10  20  50  70
Burnet Muni Airport            86  72  87  71  82 /  10  10  10  40  70
Del Rio Intl Airport           92  76  91  73  88 /  10  10  10  50  30
Georgetown Muni Airport        86  74  88  73  81 /  20  20  10  40  70
Hondo Muni Airport             89  75  90  74  86 /  10  10  20  60  60
San Marcos Muni Airport        88  74  88  72  81 /  20  10  20  50  70
La Grange - Fayette Regional   88  76  88  74  83 /  20  10  20  30  60
San Antonio Intl Airport       89  75  89  73  83 /  10  10  20  50  70
Stinson Muni Airport           89  76  90  74  85 /  10  10  20  60  70

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...Oaks
Synoptic/Grids...Allen
Public Service/Data Collection...33





000
FXUS64 KEWX 240826
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
326 AM CDT TUE MAY 24 2016

.SHORT TERM (Today through Wednesday)...
Mostly cloudy skies are prevailing across the region with ample
low-level moisture in place. There have been a couple of
observation sites reporting brief light rain and will include the
mention of sprinkles in the morning hours. For this afternoon,
things should be a bit quieter across the region. High-res
guidance shows some showers across the eastern zones once again
and will show the higher pops (20s) in this area. The dryline will
be just west of the region this afternoon and can`t rule out an
isolated thunderstorm moving into the western CWA late this
afternoon or evening. There will be a conditional threat of severe
weather as the atmosphere would support severe convection. Will
mention thunderstorms in the official forecast with only a 10 pop
as the threat is low.

On Wednesday, an upper trough will be moving east and will be
centered near southern California. Ahead of this feature, models
are progging a shortwave trough embedded in southwest flow aloft
to move into the region. This feature will help aide in the
development of shower and thunderstorm activity in the late
afternoon and evening hours out west along the dryline. There
will be a CAP in place initially but both the GFS and ECMWF are
progging decent amounts of QPF across the western CWA which
indicates the CAP is likely to break as convective temps are met.
CAPE values in the late afternoon evenings will be near 3500 J/Kg
and there will be a threat of severe storms with any activity that
develops across the northwestern CWA. Large hail would be the main
threat with steep mid-level lapse rates in place.

&&

.LONG TERM (Wednesday Night through Monday)...
For Wednesday night, there should be some sort of convective
complex ongoing assuming storms do develop in the late afternoon
hours. Severe chances would likely diminish in the overnight
period with the loss of day time heating.

Thursday and Thursday night, the previously mentioned upper
trough will be approaching West Texas and the Panhandle. As this
feature moves closer, large scale forcing for ascent will be on
the increase. The best lift will be north of the CWA and the bulk
of the storm activity should be north of the region as well.
However, there remains decent chances for thunderstorms in the
CWA especially in the evening hours. There is an enhanced risk of
severe storms just north of the region with a slight risk along
and west of the I-35 corridor. 850 winds will be from the south
around 35 knots in the afternoon with 0-3km helicity values near
250 m2/s2. In addition to a large hail risk there would also be a
possible isolated tornado risk as well.

The base of the upper trough will move into the southern plains
on Friday and as this occurs, the dryline should be able to push
farther east in the afternoon hours. This should ensure that the
bulk of the shower and storm activity will be east of I-35 mainly
east of the dryline. The dryline will retreat back to the west by
Saturday morning and the better convection chances Saturday
afternoon will be across the western half of the area. Once again,
CAPE and shear values will support the threat of severe convection
with any cells that are able to be be sustained in the boundary
layer.

On Sunday, another shortwave trough will move north of the region
and the bulk of the activity will remain north of the CWA. Can`t
rule out an isolated shower or storm and will keep a 20 PoP in the
forecast. The same can be said for Monday as most of the storms
will remain near the dryline which is expected to be west of the
region.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              88  75  89  73  85 /  20  10  20  20  60
Austin Bergstrom Intl Airport  88  75  90  74  85 /  20  10  20  20  60
New Braunfels Muni Airport     89  74  89  73  86 /  20  10  20  30  60
Burnet Muni Airport            86  73  87  71  85 /  10  10  10  20  60
Del Rio Intl Airport           92  76  93  74  90 /  10  10  20  50  30
Georgetown Muni Airport        86  74  88  73  84 /  20  10  10  20  60
Hondo Muni Airport             89  75  91  74  89 /  10  10  10  40  60
San Marcos Muni Airport        88  75  89  73  84 /  20  10  20  30  60
La Grange - Fayette Regional   88  76  88  75  85 /  20  10  20  10  50
San Antonio Intl Airport       89  75  90  74  86 /  10  10  20  30  60
Stinson Muni Airport           89  76  91  74  88 /  10  10  20  40  60

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...05
Synoptic/Grids...Hampshire





000
FXUS64 KEWX 240541
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1241 AM CDT TUE MAY 24 2016

.AVIATION...
No significant changes to ongoing TAFs. MVFR cigs will lower
further through the night to LIFR in Austin and San Antonio. DRT
will stay MVFR. There is a slight chance for light rain or drizzle
around sunrise, but probability is low and any light precip will
not change category. Improvement Wednesday will be slow and CIGs
will not rise to VFR until mid-afternoon.

&&

.PREV DISCUSSION... /ISSUED 1025 PM CDT MON MAY 23 2016/

UPDATE...
Tornado Watch 199 has been allowed to expire as convection has
dissipated over the Rio Grande Plains and the impressive supercell
complex (with -82 deg C cloud tops and echoes to 68 kft) southwest
of Eagle Pass in Mexico should stay out of our CWA. A strong cap
evident on the 00Z DRT sounding and recent aircraft soundings at
AUS and SAT suggest that only shallow convective shower activity
would be possible tonight. Hi-res models show very little
coverage overnight, so have removed POPs everywhere except for the
western Hill Country, Rio Grande Plains, and Edwards Plateau. Kept
a slight chance of thunderstorms along the border just in case
another cell tries to pop up in any remnant outflow, but the cap
should prevent this. Very isolated light showers are still
expected along the I-35 corridor tomorrow morning after sunrise,
though probably lower in coverage than the last two mornings.

PREV DISCUSSION... /ISSUED 334 PM CDT MON MAY 23 2016/

SHORT TERM (Tonight through Tuesday Night)...

Main highlight for the next 36 hours will the the slight to
marginal risk of strong and severe storms across the Rio Grande
Plains and portions of the southern Edwards Plateau late this
afternoon and evening. Main risks will be large hail, straight-
line damaging winds and a brief tornado can not be ruled out. Storm
coverage and strength is expected to decrease through late evening.

Scattered light to moderate showers are ongoing across central and
eastern areas as weak isentropic lift occurs underneath embedded
mid-level impulses in the SW flow aloft. Luckily a capping
inversion is in place and limiting vertical extent of this
activity. Farther west however, warmer low-levels resulting in
higher mixed-layer instability of 4000-5000 J/KG will be able to
ignite strong and severe storms across the Big Bend of Texas and
along the Burros Mountains. KDRT model soundings and SPC
mesoanalysis still suggest a capping inversion in place albeit
weaker. Storms should initiate farther NW of the area and on the
higher terrain where the capping is weaker and then move towards
Val Verde/Edwards late afternoon/early evening. Very large hail
could be possible given the CAPE values and lapse rates in place.
Downdraft CAPE is over 1000 J/KG that could result in pockets of
damaging straight-line winds. Low-level 0-1 km SRH is only 50-100
m2/s2 but 0-3 km SRH is upwards of 150 m2/s2 that could support
the possibility of a brief tornado in this area.

Storms are expected to weaken into the late evening and overnight
as they slowly push east/southeast towards the southern Edwards
Plateau and along the Rio Grande Plains.

Tuesday will feature slightly stronger H5 ridging as the dryline
retreats farther westward. With ridging and capping in place,
rain and thunder storm chances will be lower. However, if a storm
were to break through the capping inversion, it could become
strong. Capping will be slightly weaker over the Hill County and
the Burros again and this area will need to be monitored.

LONG TERM (Wednesday through Monday)...

Potential heavy rain event could take form late week into the
beginning of Memorial Weekend. Multiple model guidance suggests
an increasing probability of several rounds of heavy rain Thursday
and then again Friday. Please stay tuned as we approach this time
frame given the already saturated soil across the area.

Wednesday will feature additional H5 ridging while a deeper
trough develops across the desert SW of the US. A implied stronger
shortwave trough will should shift across the Rio Grande Plains
ahead of the parent low pressure system late Wednesday night to
help usher the first round of showers and storms across the
region. Greater synoptic lift coupled with PWATS increasing to
near 1.8" to 2" could lead to very efficient rainfall through the
day Thursday. A brief break may occur late Thursday night into
Friday morning but then the greatest synoptic lift will shift
across south-central Texas Friday afternoon and evening as the
base of the parent trough shift over the southern Plains. Again,
with the ongoing, and by this time likely very saturated soil,
high amounts of run off are becoming an increasing concern. A
flash flood watch may be needed for this time period. Please stay
tuned as details and rain amounts become more clear going into the
holiday weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              87  74  88  74  83 /  20  10  10  20  60
Austin Bergstrom Intl Airport  87  74  88  74  83 /  20  10  10  20  60
New Braunfels Muni Airport     87  73  88  74  83 /  20  10  10  20  60
Burnet Muni Airport            86  72  87  73  82 /  20  10  10  20  60
Del Rio Intl Airport           91  76  91  75  89 /  20  10  20  50  30
Georgetown Muni Airport        85  73  87  74  82 /  20  10  10  20  60
Hondo Muni Airport             88  74  89  75  84 /  20  10  10  40  60
San Marcos Muni Airport        86  73  88  74  82 /  20  10  10  20  60
La Grange - Fayette Regional   87  75  88  75  83 /  10  10  10  20  50
San Antonio Intl Airport       87  74  88  74  82 /  20  10  10  30  60
Stinson Muni Airport           89  75  90  75  85 /  20  10  10  30  60

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...05
Synoptic/Grids...Hampshire





000
FXUS64 KEWX 240325
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1025 PM CDT MON MAY 23 2016

.UPDATE...
Tornado Watch 199 has been allowed to expire as convection has
dissipated over the Rio Grande Plains and the impressive supercell
complex (with -82 deg C cloud tops and echoes to 68 kft) southwest
of Eagle Pass in Mexico should stay out of our CWA. A strong cap
evident on the 00Z DRT sounding and recent aircraft soundings at
AUS and SAT suggest that only shallow convective shower activity
would be possible tonight. Hi-res modesls show very little
coverage overnight, so have removed POPs everywhere except for the
western Hill Country, Rio Grande Plains, and Edwards Plateau.
Kept a slight chance of thunderstorms along the border just in
case another cell tries to pop up in any remnant outflow, but the
cap should prevent this. Very isolated light showers are still
expected along the I-35 corridor tomorrow morning after sunrise,
though probably lower in coverage than the last two mornings.

&&

.PREV DISCUSSION... /ISSUED 700 PM CDT MON MAY 23 2016/

AVIATION.../00Z TAFS/
Isolated light showers are ending for the I-35 TAF sites as their
ceilings remain borderline MVFR-VFR with gusty winds to 20-25 kts
before transitiong to MVFR and less gusty winds by 3Z. DRT may
have to contend with severe TSRA tonight, although likely not for
a few hours as the supercell and showers to its S-SW should miss
the site. However, VCTS is included between 3-7Z as a right split
supercell entering far NW Val Verde County may turn further right
to affect DRT if the air mass does not stabilize before then.

All sites will lower to IFR by 7-8Z, with a few models suggesting
light showers will occur at the I-35 TAF sites once again between
12-15Z to cause borderline LIFR-IFR ceilings and visibilities.
Thus, have included this in their TAFS based on persistence over
the last few days. Ceilings should improve to MVFR around 17Z,
with most sites becoming VFR by 19-20Z except maybe at AUS where
conditions are less optimistic. Stronger capping beneath the ridge
should again prevent development of TSRA except maybe at DRT, but
chances are too low to include at this time.

PREV DISCUSSION... /ISSUED 334 PM CDT MON MAY 23 2016/

SHORT TERM (Tonight through Tuesday Night)...

Main highlight for the next 36 hours will the the slight to
marginal risk of strong and severe storms across the Rio Grande
Plains and portions of the southern Edwards Plateau late this
afternoon and evening. Main risks will be large hail, straight-
line damaging winds and a brief tornado can not be ruled out. Storm
coverage and strength is expected to decrease through late evening.

Scattered light to moderate showers are ongoing across central and
eastern areas as weak isentropic lift occurs underneath embedded
mid-level impulses in the SW flow aloft. Luckily a capping
inversion is in place and limiting vertical extent of this
activity. Farther west however, warmer low-levels resulting in
higher mixed-layer instability of 4000-5000 J/KG will be able to
ignite strong and severe storms across the Big Bend of Texas and
along the Burros Mountains. KDRT model soundings and SPC
mesoanalysis still suggest a capping inversion in place albeit
weaker. Storms should initiate farther NW of the area and on the
higher terrain where the capping is weaker and then move towards
Val Verde/Edwards late afternoon/early evening. Very large hail
could be possible given the CAPE values and lapse rates in place.
Downdraft CAPE is over 1000 J/KG that could result in pockets of
damaging straight-line winds. Low-level 0-1 km SRH is only 50-100
m2/s2 but 0-3 km SRH is upwards of 150 m2/s2 that could support
the possibility of a brief tornado in this area.

Storms are expected to weaken into the late evening and overnight
as they slowly push east/southeast towards the southern Edwards
Plateau and along the Rio Grande Plains.

Tuesday will feature slightly stronger H5 ridging as the dryline
retreats farther westward. With ridging and capping in place,
rain and thunder storm chances will be lower. However, if a storm
were to break through the capping inversion, it could become
strong. Capping will be slightly weaker over the Hill County and
the Burros again and this area will need to be monitored.

LONG TERM (Wednesday through Monday)...

Potential heavy rain event could take form late week into the
beginning of Memorial Weekend. Multiple model guidance suggests
an increasing probability of several rounds of heavy rain Thursday
and then again Friday. Please stay tuned as we approach this time
frame given the already saturated soil across the area.

Wednesday will feature additional H5 ridging while a deeper
trough develops across the desert SW of the US. A implied stronger
shortwave trough will should shift across the Rio Grande Plains
ahead of the parent low pressure system late Wednesday night to
help usher the first round of showers and storms across the
region. Greater synoptic lift coupled with PWATS increasing to
near 1.8" to 2" could lead to very efficient rainfall through the
day Thursday. A brief break may occur late Thursday night into
Friday morning but then the greatest synoptic lift will shift
across south-central Texas Friday afternoon and evening as the
base of the parent trough shift over the southern Plains. Again,
with the ongoing, and by this time likely very saturated soil,
high amounts of run off are becoming an increasing concern. A
flash flood watch may be needed for this time period. Please stay
tuned as details and rain amounts become more clear going into the
holiday weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              86  73  87  74  88 /  20  10  20  10  10
Austin Bergstrom Intl Airport  86  73  87  74  88 /  20  10  20  10  10
New Braunfels Muni Airport     87  73  87  73  88 /  20  10  20  10  10
Burnet Muni Airport            83  71  86  72  87 /  30  10  20  10  10
Del Rio Intl Airport           90  76  91  76  91 /  30  20  20  10  20
Georgetown Muni Airport        85  72  85  73  87 /  30  10  20  10  10
Hondo Muni Airport             89  73  88  74  89 /  20  10  20  10  10
San Marcos Muni Airport        86  72  86  73  88 /  20  10  20  10  10
La Grange - Fayette Regional   86  74  87  75  88 /  20  10  10  10  10
San Antonio Intl Airport       87  73  87  74  88 /  20  10  20  10  10
Stinson Muni Airport           89  74  89  75  90 /  20  10  20  10  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...Runyen
Synoptic/Grids...LH
Public Service/Data Collection...Treadway





000
FXUS64 KEWX 240000
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
700 PM CDT MON MAY 23 2016

.AVIATION.../00Z TAFS/
Isolated light showers are ending for the I-35 TAF sites as their
ceilings remain borderline MVFR-VFR with gusty winds to 20-25 kts
before transitiong to MVFR and less gusty winds by 3Z. DRT may
have to contend with severe TSRA tonight, although likely not for
a few hours as the supercell and showers to its S-SW should miss
the site. However, VCTS is included between 3-7Z as a right split
supercell entering far NW Val Verde County may turn further right
to affect DRT if the air mass does not stabilize before then.

All sites will lower to IFR by 7-8Z, with a few models suggesting
light showers will occur at the I-35 TAF sites once again between
12-15Z to cause borderline LIFR-IFR ceilings and visibilities.
Thus, have included this in their TAFS based on persistence over
the last few days. Ceilings should improve to MVFR around 17Z,
with most sites becoming VFR by 19-20Z except maybe at AUS where
conditions are less optimistic. Stronger capping beneath the ridge
should again prevent development of TSRA except maybe at DRT, but
chances are too low to include at this time.

&&

.PREV DISCUSSION... /ISSUED 334 PM CDT MON MAY 23 2016/

SHORT TERM (Tonight through Tuesday Night)...

Main highlight for the next 36 hours will the the slight to
marginal risk of strong and severe storms across the Rio Grande
Plains and portions of the southern Edwards Plateau late this
afternoon and evening. Main risks will be large hail, straight-
line damaging winds and a brief tornado can not be ruled out. Storm
coverage and strength is expected to decrease through late evening.

Scattered light to moderate showers are ongoing across central and
eastern areas as weak isentropic lift occurs underneath embedded
mid-level impulses in the SW flow aloft. Luckily a capping
inversion is in place and limiting vertical extent of this
activity. Farther west however, warmer low-levels resulting in
higher mixed-layer instability of 4000-5000 J/KG will be able to
ignite strong and severe storms across the Big Bend of Texas and
along the Burros Mountains. KDRT model soundings and SPC
mesoanalysis still suggest a capping inversion in place albeit
weaker. Storms should initiate farther NW of the area and on the
higher terrain where the capping is weaker and then move towards
Val Verde/Edwards late afternoon/early evening. Very large hail
could be possible given the CAPE values and lapse rates in place.
Downdraft CAPE is over 1000 J/KG that could result in pockets of
damaging straight-line winds. Low-level 0-1 km SRH is only 50-100
m2/s2 but 0-3 km SRH is upwards of 150 m2/s2 that could support
the possibility of a brief tornado in this area.

Storms are expected to weaken into the late evening and overnight
as they slowly push east/southeast towards the southern Edwards
Plateau and along the Rio Grande Plains.

Tuesday will feature slightly stronger H5 ridging as the dryline
retreats farther westward. With ridging and capping in place,
rain and thunder storm chances will be lower. However, if a storm
were to break through the capping inversion, it could become
strong. Capping will be slightly weaker over the Hill County and
the Burros again and this area will need to be monitored.

LONG TERM (Wednesday through Monday)...

Potential heavy rain event could take form late week into the
beginning of Memorial Weekend. Multiple model guidance suggests
an increasing probability of several rounds of heavy rain Thursday
and then again Friday. Please stay tuned as we approach this time
frame given the already saturated soil across the area.

Wednesday will feature additional H5 ridging while a deeper
trough develops across the desert SW of the US. A implied stronger
shortwave trough will should shift across the Rio Grande Plains
ahead of the parent low pressure system late Wednesday night to
help usher the first round of showers and storms across the
region. Greater synoptic lift coupled with PWATS increasing to
near 1.8" to 2" could lead to very efficient rainfall through the
day Thursday. A brief break may occur late Thursday night into
Friday morning but then the greatest synoptic lift will shift
across south-central Texas Friday afternoon and evening as the
base of the parent trough shift over the southern Plains. Again,
with the ongoing, and by this time likely very saturated soil,
high amounts of run off are becoming an increasing concern. A
flash flood watch may be needed for this time period. Please stay
tuned as details and rain amounts become more clear going into the
holiday weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              86  73  87  74  88 /  20  10  20  10  10
Austin Bergstrom Intl Airport  86  73  87  74  88 /  20  10  20  10  10
New Braunfels Muni Airport     87  73  87  73  88 /  20  10  20  10  10
Burnet Muni Airport            83  71  86  72  87 /  30  20  20  10  10
Del Rio Intl Airport           90  76  91  76  91 /  30  30  20  10  20
Georgetown Muni Airport        85  72  85  73  87 /  30  10  20  10  10
Hondo Muni Airport             89  73  88  74  89 /  20  10  20  10  10
San Marcos Muni Airport        86  72  86  73  88 /  20  10  20  10  10
La Grange - Fayette Regional   86  74  87  75  88 /  20  10  10  10  10
San Antonio Intl Airport       87  73  87  74  88 /  20  10  20  10  10
Stinson Muni Airport           89  74  89  75  90 /  20  10  20  10  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...LH
Synoptic/Grids...Runyen
Public Service/Data Collection...Treadway





000
FXUS64 KEWX 231749
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1249 PM CDT MON MAY 23 2016

.AVIATION...
Mainly MVFR cigs rise to low end VFR mid to late afternoon. Isold
shra/tsra will develop over the Serranias del Burro west of KDRT
this afternoon. Kept mention out KDRT TAF as prob is low. However,
will monitor radar/model trends for possible update to mention.
Cigs lower to MVFR this evening and IFR overnight. Some patchy
-radz br is possible and may lower cigs to LIFR and vsbys to
IFR/MVFR early Tuesday morning. However, left mention out at TAFs
as probs are low. S to SE winds 5 to 15 Kts prevail with gusts up
to 24 Kts possible.

&&

.PREV DISCUSSION... /ISSUED 637 AM CDT MON MAY 23 2016/

AVIATION...
Austin and San Antonio airports starting off IFR and expect DRT to
join them within the next hour or two. Improvement will be slow
and they should all be VFR by early afternoon. There is a slight
chance for convection this afternoon, but probability is too low
to include in TAF. Low CIGs will develop again this evening.

PREV DISCUSSION... /ISSUED 435 AM CDT MON MAY 23 2016/

SHORT TERM (Today through Tuesday)...
Moist conditions are in place early this morning with dewpoints in
the mid 60s to lower 70s across all of south central Texas. Cloud
cover is also on the increase and a few showers are noted along
the Rio Grande to the north of Del Rio. Cloud cover will be slow
to dissipate today as southerly flow in the low-levels remains
intact today. Any breaks in the cloud cover will help to
destabilize the lower levels this afternoon. Most activity should
remain isolated and for now, we will keep rain chances low. We
could see a strong to severe storm this afternoon and early
evening, with the best shot limited to the southern Edwards
Plateau and Rio Grande plains. Some of the hi-res models are
showing convection developing over the higher terrain west of the
Rio Grande, then moving eastward into the Rio Grande plains and
southern Edwards plateau during the evening hours. The 0-6km bulk
shear values would tend to favor a few supercells across the
mentioned region. The main severe weather concerns will be large
hail and damaging winds. These storms will be tied closely to
daytime heating and we expect most activity will decrease by late
evening. On Tuesday, little overall change in the synoptic scale weather
pattern is expected. We do expect the subtropical ridge axis to
strengthen slightly over southern Texas and this should nudge the
more active southwest flow aloft a little farther north. Still,
can`t rule out a strong storm or two west of I-35. Similar to
today, suspect the best shot at severe storm development will be
across the southern Edwards plateau and Rio Grande plains. High
temperatures in the lower to possibly mid 90s along the Rio Grande
will produce heat index values of 100 to 105 Tuesday afternoon.

LONG TERM (Tuesday Night through Sunday)...
Southwesterly flow aloft will continue thorough the remainder of
the forecast period. The subtropical ridge axis should be strong
enough to limit convection during the daytime hours on Wednesday.
Similar to Tuesday, we could see afternoon heat index values of
100-105 along the Rio Grande. For the evening and overnight
hours, the models continue to trend wetter across the region.
Convection developing over the higher terrain west of the Rio
Grande is expected to shift eastward. Given a decent low- level
jet, this activity should be able to maintain during the evening
hours into early Thursday morning. Rain chances continue to
improve on Friday as an active southwest flow aloft and the
dryline mixing eastward during the afternoon hours should result
in scattered convection. The dryline may not mix as far east as
previously anticipated, but will still serve as a focus for
convection. While we can`t rule out the possibility for strong to
severe storms late this week, we`ll also need to monitor for
locally heavy rainfall given well above normal moisture in the
atmosphere. Rain chances will continue into the upcoming weekend
given continued southwest flow aloft.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              86  73  88  73  90 /  20  10  10  10  10
Austin Bergstrom Intl Airport  86  73  88  74  89 /  20  10  10  10  10
New Braunfels Muni Airport     87  73  88  74  90 /  20  10  10  10  10
Burnet Muni Airport            83  71  86  72  88 /  30  20  10  10  10
Del Rio Intl Airport           90  75  93  76  93 /  30  20  20  10  10
Georgetown Muni Airport        85  72  86  73  88 /  30  10  10  10  10
Hondo Muni Airport             89  73  90  74  91 /  20  20  10  10  10
San Marcos Muni Airport        86  72  87  73  90 /  20  10  10  10  10
La Grange - Fayette Regional   86  74  88  75  89 /  20  10  10  10  10
San Antonio Intl Airport       87  73  89  73  90 /  20  10  10  10  10
Stinson Muni Airport           89  74  90  75  91 /  20  10  10  10  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...04
Synoptic/Grids...Allen
Public Service/Data Collection...30





000
FXUS64 KEWX 230935
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
435 AM CDT MON MAY 23 2016

.SHORT TERM (Today through Tuesday)...
Moist conditions are in place early this morning with dewpoints in
the mid 60s to lower 70s across all of south central Texas. Cloud
cover is also on the increase and a few showers are noted along
the Rio Grande to the north of Del Rio. Cloud cover will be slow
to dissipate today as southerly flow in the low-levels remains
intact today. Any breaks in the cloud cover will help to
destabilize the lower levels this afternoon. Most activity should
remain isolated and for now, we will keep rain chances low. We
could see a strong to severe storm this afternoon and early
evening, with the best shot limited to the southern Edwards
Plateau and Rio Grande plains. Some of the hi-res models are
showing convection developing over the higher terrain west of the
Rio Grande, then moving eastward into the Rio Grande plains and
southern Edwards plateau during the evening hours. The 0-6km bulk
shear values would tend to favor a few supercells across the
mentioned region. The main severe weather concerns will be large
hail and damaging winds. These storms will be tied closely to
daytime heating and we expect most activity will decrease by late
evening. On Tuesday, little overall change in the synoptic scale weather
pattern is expected. We do expect the subtropical ridge axis to
strengthen slightly over southern Texas and this should nudge the
more active southwest flow aloft a little farther north. Still,
can`t rule out a strong storm or two west of I-35. Similar to
today, suspect the best shot at severe storm development will be
across the southern Edwards plateau and Rio Grande plains. High
temperatures in the lower to possibly mid 90s along the Rio Grande
will produce heat index values of 100 to 105 Tuesday afternoon.

&&

.LONG TERM (Tuesday Night through Sunday)...
Southwesterly flow aloft will continue thorough the remainder of
the forecast period. The subtropical ridge axis should be strong
enough to limit convection during the daytime hours on Wednesday.
Similar to Tuesday, we could see afternoon heat index values of
100-105 along the Rio Grande. For the evening and overnight
hours, the models continue to trend wetter across the region.
Convection developing over the higher terrain west of the Rio
Grande is expected to shift eastward. Given a decent low- level
jet, this activity should be able to maintain during the evening
hours into early Thursday morning. Rain chances continue to
improve on Friday as an active southwest flow aloft and the
dryline mixing eastward during the afternoon hours should result
in scattered convection. The dryline may not mix as far east as
previously anticipated, but will still serve as a focus for
convection. While we can`t rule out the possibility for strong to
severe storms late this week, we`ll also need to monitor for
locally heavy rainfall given well above normal moisture in the
atmosphere. Rain chances will continue into the upcoming weekend
given continued southwest flow aloft.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              86  73  88  73  90 /  20  10  10  10  10
Austin Bergstrom Intl Airport  86  73  88  74  89 /  20  10  10  10  10
New Braunfels Muni Airport     87  73  88  74  90 /  20  10  10  10  10
Burnet Muni Airport            83  71  86  72  88 /  20  20  10  10  10
Del Rio Intl Airport           90  75  93  76  93 /  20  20  20  10  10
Georgetown Muni Airport        85  72  86  73  88 /  20  10  10  10  10
Hondo Muni Airport             89  73  90  74  91 /  20  20  10  10  10
San Marcos Muni Airport        86  72  87  73  90 /  20  10  10  10  10
La Grange - Fayette Regional   86  74  88  75  89 /  20  10  10  10  10
San Antonio Intl Airport       87  73  89  73  90 /  20  10  10  10  10
Stinson Muni Airport           89  74  90  75  91 /  20  10  10  10  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...05
Synoptic/Grids...24





000
FXUS64 KEWX 230549
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1249 AM CDT MON MAY 23 2016

.AVIATION...
Strong southeasterly flow in the low levels has MVFR CIGs
developing at all terminals. CIGs will drop to IFR near sunrise.
Slow improvement in flying category early this afternoon. Low
CIGs will redevelop late this evening.

&&

.PREV DISCUSSION... /ISSUED 937 PM CDT SUN MAY 22 2016/

UPDATE...What is left of the outflow boundary is producing some
stray showers this evening across Williamson and Bexar counties,
which are gradually weakening. The earlier left splitting
supercell across Val Verde county has dissipated. Expect storms
over the SJT moving southeast to weaken and possibly dissipate
before reaching the northern CWA. Have generally lowered pops
late this evening and overnight, with only stray/isolated coverage
confined mainly to the Hill Country and Rio Grande.

PREV DISCUSSION... /ISSUED 257 PM CDT SUN MAY 22 2016/

SHORT TERM (Tonight through Monday Night)...

Low chances for thunderstorms will continue tonight through Monday
as a weak ridging feature aloft over S TX keeps SW flow aloft and
a teleconnection with the Pacific tropics. Higher chances for
showers are expected this afternoon/evening with a subtle drying
trend to follow into the early part of the work week.

This afternoon, a pooling of low level moisture is concentrating
daytime showers generally along and east of Hwy 281, but the area
is shifting slowly west as is suggested by the hi-res model
solutions. There is poor agreement on where the stronger storms
develop, and with the cap holding over most areas, there is a
chance for no thunderstorms developing at all. Nevertheless, the
breaking of the cap could lead to a brief strong to severe storm,
with slow forecast storm motions likely preventing supercell
development over most of the area. By mid evening some outflow
induced dryline convection to the north and/or higher terrain
convection west of DRT could lead to a supercell or two, as most
models show convective focal points shifting to the North and West
with time and stability increasing over the Coastal Prairies.

Lower overall rain chances are forecast for Monday/Monday night,
with the non-NAM model solutions suggesting less low level
moisture convergence. The high CAPE/low shear environment still
capable of generating an isolated severe storm or two. The
presence of abundant clouds through much of the day should also
help keep convective temps at bay and help with capping.

LONG TERM (Tuesday through Sunday)...

Model consensus shows Tuesday as the most stable day of the week
with dprog/dt analysis showing the mid level height fields build
with time. the stability should gradually weaken to the west as
the ridge axis shifts east by late Wednesday. A few strong storms
are suggested for Wednesday evening near the Rio Grande,
especially by the GFS, but models show better agreement on
destabilization occurring Thursday into Friday in shifting the
persistent upper troughing feature east from the SWRN US into TX.
This pattern could lead to a heavy rain/flash flood threat given
the enhanced multi-day rain chances above normal soil moisture
levels and stream flows. The trough is shown to lift north and
become increasingly shallow, so will prefer to keep most of the
rain chances out of the likely category for now. Medium range
models show varying degrees of stability heading into the weekend
with the deterministic GFS showing a drier trend than the ECMWF.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              87  73  87  74  89 /  20  10  20  10  10
Austin Bergstrom Intl Airport  87  73  87  74  89 /  20  10  20  10  10
New Braunfels Muni Airport     88  73  87  74  89 /  20  10  20  10  10
Burnet Muni Airport            85  71  85  72  88 /  20  10  20  10  10
Del Rio Intl Airport           89  74  91  75  93 /  20  20  10  10  10
Georgetown Muni Airport        86  72  86  73  88 /  20  10  20  10  10
Hondo Muni Airport             89  73  89  74  92 /  20  20  10  10  10
San Marcos Muni Airport        87  73  87  74  89 /  20  10  20  10  10
La Grange - Fayette Regional   87  74  87  76  88 /  30  -   20  10  10
San Antonio Intl Airport       88  73  88  74  90 /  20  10  20  10  10
Stinson Muni Airport           90  74  89  75  91 /  20  10  20  10  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...05
Synoptic/Grids...24





000
FXUS64 KEWX 230237
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
937 PM CDT SUN MAY 22 2016

.UPDATE...What is left of the outflow boundary is producing some
stray showers this evening across Williamson and Bexar counties,
which are gradually weakening. The earlier left splitting
supercell across Val Verde county has dissipated. Expect storms
over the SJT moving southeast to weaken and possibly dissipate
before reaching the northern CWA. Have generally lowered pops
late this evening and overnight, with only stray/isolated coverage
confined mainly to the Hill Country and Rio Grande.

&&

.PREV DISCUSSION... /ISSUED 703 PM CDT SUN MAY 22 2016/

AVIATION.../00Z_TAFS/
Very isolated SHRA will affect the I-35 corridor over the next
few hours as a weak outflow boundary that just passed BAZ moves
west through SAT/SSF by 1Z. TSRA is not anticipated as midlevel
capping has prevented deeper convection and lower levels should
stabilize with loss of daytime heating and stabilizing effects of
the weak outflow boundary. Left and right split supercells west
of DRT will miss that site, so TSRA are not expected there either.

Ceilings will be the main issue for the overnight and morning
hours. DRT is already at MVFR and the I-35 sites will lower by 4Z,
with all sites lowering to IFR by 8Z with borderline LIFR/MVFR
conditions a few hours after sunrise. Ceilings will recover slowly
similar to today, becoming MVFR after 16Z and VFR after 19-20Z
with gusty SE winds to 20-25 knots in DRT during the afternoon.

PREV DISCUSSION... /ISSUED 257 PM CDT SUN MAY 22 2016/

SHORT TERM (Tonight through Monday Night)...

Low chances for thunderstorms will continue tonight through Monday
as a weak ridging feature aloft over S TX keeps SW flow aloft and
a teleconnection with the Pacific tropics. Higher chances for
showers are expected this afternoon/evening with a subtle drying
trend to follow into the early part of the work week.

This afternoon, a pooling of low level moisture is concentrating
daytime showers generally along and east of Hwy 281, but the area
is shifting slowly west as is suggested by the hi-res model
solutions. There is poor agreement on where the stronger storms
develop, and with the cap holding over most areas, there is a
chance for no thunderstorms developing at all. Nevertheless, the
breaking of the cap could lead to a brief strong to severe storm,
with slow forecast storm motions likely preventing supercell
development over most of the area. By mid evening some outflow
induced dryline convection to the north and/or higher terrain
convection west of DRT could lead to a supercell or two, as most
models show convective focal points shifting to the North and West
with time and stability increasing over the Coastal Prairies.

Lower overall rain chances are forecast for Monday/Monday night,
with the non-NAM model solutions suggesting less low level
moisture convergence. The high CAPE/low shear environment still
capable of generating an isolated severe storm or two. The
presence of abundant clouds through much of the day should also
help keep convective temps at bay and help with capping.

LONG TERM (Tuesday through Sunday)...

Model consensus shows Tuesday as the most stable day of the week
with dprog/dt analysis showing the mid level height fields build
with time. the stability should gradually weaken to the west as
the ridge axis shifts east by late Wednesday. A few strong storms
are suggested for Wednesday evening near the Rio Grande,
especially by the GFS, but models show better agreement on
destabilization occurring Thursday into Friday in shifting the
persistent upper troughing feature east from the SWRN US into TX.
This pattern could lead to a heavy rain/flash flood threat given
the enhanced multi-day rain chances above normal soil moisture
levels and stream flows. The trough is shown to lift north and
become increasingly shallow, so will prefer to keep most of the
rain chances out of the likely category for now. Medium range
models show varying degrees of stability heading into the weekend
with the deterministic GFS showing a drier trend than the ECMWF.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              73  87  73  87  74 /  20  20  10  20  10
Austin Bergstrom Intl Airport  72  87  73  87  74 /  20  20  10  20  10
New Braunfels Muni Airport     72  88  73  87  74 /  20  20  10  20  10
Burnet Muni Airport            70  85  71  85  72 /  20  20  10  20  10
Del Rio Intl Airport           74  89  74  91  75 /  20  20  20  10  10
Georgetown Muni Airport        71  86  72  86  73 /  20  20  10  20  10
Hondo Muni Airport             73  89  73  89  74 /  20  20  20  10  10
San Marcos Muni Airport        72  87  73  87  74 /  20  20  10  20  10
La Grange - Fayette Regional   73  87  74  87  76 /  10  30  -   20  10
San Antonio Intl Airport       74  88  73  88  74 /  20  20  10  20  10
Stinson Muni Airport           74  90  74  89  75 /  10  20  10  20  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...LH
Synoptic/Grids...Runyen
Public Service/Data Collection...Treadway





000
FXUS64 KEWX 230003
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
703 PM CDT SUN MAY 22 2016

.AVIATION.../00Z_TAFS/
Very isolated SHRA will affect the I-35 corridor over the next
few hours as a weak outflow boundary that just passed BAZ moves
west through SAT/SSF by 1Z. TSRA is not anticipated as midlevel
capping has prevented deeper convection and lower levels should
stabilize with loss of daytime heating and stabilizing effects of
the weak outflow boundary. Left and right split supercells west
of DRT will miss that site, so TSRA are not expected there either.

Ceilings will be the main issue for the overnight and morning
hours. DRT is already at MVFR and the I-35 sites will lower by 4Z,
with all sites lowering to IFR by 8Z with borderline LIFR/MVFR
conditions a few hours after sunrise. Ceilings will recover slowly
similar to today, becoming MVFR after 16Z and VFR after 19-20Z
with gusty SE winds to 20-25 knots in DRT during the afternoon.


&&

.PREV DISCUSSION... /ISSUED 257 PM CDT SUN MAY 22 2016/

SHORT TERM (Tonight through Monday Night)...

Low chances for thunderstorms will continue tonight through Monday
as a weak ridging feature aloft over S TX keeps SW flow aloft and
a teleconnection with the Pacific tropics. Higher chances for
showers are expected this afternoon/evening with a subtle drying
trend to follow into the early part of the work week.

This afternoon, a pooling of low level moisture is concentrating
daytime showers generally along and east of Hwy 281, but the area
is shifting slowly west as is suggested by the hi-res model
solutions. There is poor agreement on where the stronger storms
develop, and with the cap holding over most areas, there is a
chance for no thunderstorms developing at all. Nevertheless, the
breaking of the cap could lead to a brief strong to severe storm,
with slow forecast storm motions likely preventing supercell
development over most of the area. By mid evening some outflow
induced dryline convection to the north and/or higher terrain
convection west of DRT could lead to a supercell or two, as most
models show convective focal points shifting to the North and West
with time and stability increasing over the Coastal Prairies.

Lower overall rain chances are forecast for Monday/Monday night,
with the non-NAM model solutions suggesting less low level
moisture convergence. The high CAPE/low shear environment still
capable of generating an isolated severe storm or two. The
presence of abundant clouds through much of the day should also
help keep convective temps at bay and help with capping.

LONG TERM (Tuesday through Sunday)...

Model consensus shows Tuesday as the most stable day of the week
with dprog/dt analysis showing the mid level height fields build
with time. the stability should gradually weaken to the west as
the ridge axis shifts east by late Wednesday. A few strong storms
are suggested for Wednesday evening near the Rio Grande,
especially by the GFS, but models show better agreement on
destabilization occurring Thursday into Friday in shifting the
persistent upper troughing feature east from the SWRN US into TX.
This pattern could lead to a heavy rain/flash flood threat given
the enhanced multi-day rain chances above normal soil moisture
levels and stream flows. The trough is shown to lift north and
become increasingly shallow, so will prefer to keep most of the
rain chances out of the likely category for now. Medium range
models show varying degrees of stability heading into the weekend
with the deterministic GFS showing a drier trend than the ECMWF.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              87  73  87  73  87 /  40  30  20  10  20
Austin Bergstrom Intl Airport  86  72  87  73  87 /  40  30  20  10  20
New Braunfels Muni Airport     88  72  88  73  87 /  40  20  20  10  20
Burnet Muni Airport            84  70  85  71  85 /  40  30  20  10  20
Del Rio Intl Airport           89  74  89  74  91 /  30  30  20  20  10
Georgetown Muni Airport        85  71  86  72  86 /  40  30  20  10  20
Hondo Muni Airport             88  73  89  73  89 /  30  20  20  20  10
San Marcos Muni Airport        87  72  87  73  87 /  40  20  20  10  20
La Grange - Fayette Regional   86  73  87  74  87 /  50  20  30  -   20
San Antonio Intl Airport       88  74  88  73  88 /  40  20  20  10  20
Stinson Muni Airport           88  74  90  74  89 /  40  20  20  10  20

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...LH
Synoptic/Grids...Runyen
Public Service/Data Collection...Treadway





000
FXUS64 KEWX 221957
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
257 PM CDT SUN MAY 22 2016

.SHORT TERM (Tonight through Monday Night)...

Low chances for thunderstorms will continue tonight through Monday
as a weak ridging feature aloft over S TX keeps SW flow aloft and
a teleconnection with the Pacific tropics. Higher chances for
showers are expected this afternoon/evening with a subtle drying
trend to follow into the early part of the work week.

This afternoon, a pooling of low level moisture is concentrating
daytime showers generally along and east of Hwy 281, but the area
is shifting slowly west as is suggested by the hi-res model
solutions. There is poor agreement on where the stronger storms
develop, and with the cap holding over most areas, there is a
chance for no thunderstorms developing at all. Nevertheless, the
breaking of the cap could lead to a brief strong to severe storm,
with slow forecast storm motions likely preventing supercell
development over most of the area. By mid evening some outflow
induced dryline convection to the north and/or higher terrain
convection west of DRT could lead to a supercell or two, as most
models show convective focal points shifting to the North and West
with time and stability increasing over the Coastal Prairies.

Lower overall rain chances are forecast for Monday/Monday night,
with the non-NAM model solutions suggesting less low level
moisture convergence. The high CAPE/low shear environment still
capable of generating an isolated severe storm or two. The
presence of abundant clouds through much of the day should also
help keep convective temps at bay and help with capping.

&&

.LONG TERM (Tuesday through Sunday)...

Model consensus shows Tuesday as the most stable day of the week
with dprog/dt analysis showing the mid level height fields build
with time. the stability should gradually weaken to the west as
the ridge axis shifts east by late Wednesday. A few strong storms
are suggested for Wednesday evening near the Rio Grande,
especially by the GFS, but models show better agreement on
destabilization occurring Thursday into Friday in shifting the
persistent upper troughing feature east from the SWRN US into TX.
This pattern could lead to a heavy rain/flash flood threat given
the enhanced multi-day rain chances above normal soil moisture
levels and stream flows. The trough is shown to lift north and
become increasingly shallow, so will prefer to keep most of the
rain chances out of the likely category for now. Medium range
models show varying degrees of stability heading into the weekend
with the deterministic GFS showing a drier trend than the ECMWF.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              73  87  73  87  74 /  30  20  10  20  10
Austin Bergstrom Intl Airport  72  87  73  87  74 /  30  20  10  20  10
New Braunfels Muni Airport     72  88  73  87  74 /  20  20  10  20  10
Burnet Muni Airport            70  85  71  85  72 /  30  20  10  20  10
Del Rio Intl Airport           74  89  74  91  75 /  30  20  20  10  10
Georgetown Muni Airport        71  86  72  86  73 /  30  20  10  20  10
Hondo Muni Airport             73  89  73  89  74 /  20  20  20  10  10
San Marcos Muni Airport        72  87  73  87  74 /  20  20  10  20  10
La Grange - Fayette Regional   73  87  74  87  76 /  20  30  -   20  10
San Antonio Intl Airport       74  88  73  88  74 /  20  20  10  20  10
Stinson Muni Airport           74  90  74  89  75 /  20  20  10  20  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...Allen
Synoptic/Grids...Oaks
Public Service/Data Collection...30





000
FXUS64 KEWX 221758 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
1258 PM CDT SUN MAY 22 2016

.AVIATION.../18Z TAF CYCLE/

MVFR conditions mostly prevail across the region with a few
pockets of VFR beginning to develop as the low stratus slowly
mixes out and upwards vertically. The slowly climbing trend will
continue through the afternoon and early evening but low-end VFR
will likely be the best ceilings improve to today. Isolated/
scattered SHRA/TSRA is beginning to develop east and north of
KAUS and is the most likely terminal to possibly be impacted by
weather today. KSAT/KSSF will have a small chance of SHRA this
afternoon but likelihood is too low to directly include in TAFs
at this time. In addition, SHRA should occur near KDRT along the
Burro mountains and will need to monitor for any possible
amendments. Another batch of TSRA could shift across the Hill
Country this evening but should stay west of KSAT. However, trends
will need to be monitored. Overall, activity will decrease through
the early morning hours Monday.

Ceiling wise, expect a quick return to MVFR by 03/04Z tonight and
then patchy IFR conditions through 12-15Z before climbing slowly
back to high-end MVFR to low-end VFR into the afternoon hours.
Surface winds will be southeast at 10 KTs or less.

&&

PREV DISCUSSION... /ISSUED 408 AM CDT SUN MAY 22 2016/

SHORT TERM (Today through Monday)...
The early morning surface observations show plenty of low-level
moisture in place with dew points at or above 70 degrees as of 3
AM. Some patchy fog is also developing and given moist conditions
in the boundary layer, we will include patchy fog in the forecast
through mid-morning. In addition, we could see some isolated
showers develop this morning and we have kept a 20% chance in the
forecast. For this afternoon, we expect additional convection to
develop as the capping inversion should erode fairly quickly with
daytime heating. Convection could also be aided by a possible
outflow boundary moving southward from west central Texas. A few
strong to severe storms remain possible, especially along and west
of the I-35 corridor. Fairly weak steering could also result in
slow moving storms producing locally heavy rainfall. Most
convection should weaken by late evening as boundary layer cooling
helps to stabilize the low-levels. Little change in the overall
weather pattern is expected on Monday. Similar to today, we can`t
rule out some additional strong to possibly severe storms in the
afternoon and evening hours. For now, it appears the Hill Country
may have a slightly better chance for convection as remnant
outflow boundaries could impact this area.

LONG TERM (Monday Night through Saturday)...
A fairly active southwest flow aloft is expected to continue
across south central Texas through the week. This pattern is
expected to result in a continued chance for showers and
thunderstorms for most areas each day this week. The short and
medium range models have trended a little drier on Tuesday and
Wednesday as the subtropical ridge axis briefly builds across the
western Gulf of Mexico. The models then show an increase in mid-
level shortwaves moving into the region on Thursday and Friday.
This along with the dryline becoming active across our region
should result in increased coverage of showers and thunderstorms
late in the work week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              71  87  71  88  73 /  20  20  10  10  10
Austin Bergstrom Intl Airport  71  86  71  88  73 /  20  20  10  10  10
New Braunfels Muni Airport     71  88  71  88  74 /  20  20  10  10  10
Burnet Muni Airport            70  85  70  86  71 /  20  20  10  10  10
Del Rio Intl Airport           73  89  73  92  74 /  30  20  10  -   -
Georgetown Muni Airport        71  86  70  87  72 /  20  20  10  10  10
Hondo Muni Airport             72  88  71  90  73 /  20  20  10  10  10
San Marcos Muni Airport        71  86  71  88  73 /  20  20  10  10  10
La Grange - Fayette Regional   71  87  73  88  75 /  20  30  10  10  10
San Antonio Intl Airport       72  88  72  88  73 /  20  20  10  10  10
Stinson Muni Airport           73  89  73  89  74 /  20  20  10  10  10

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Mesoscale/Aviation...Allen
Synoptic/Grids...Oaks
Public Service/Data Collection...30





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